In today’s world, there are many types of digital devices: desktop and laptop
computers, smartphones, tablets, and so on. A harmonious and efficient user
experience is only possible when the software’s user interface is tailored to
each device’s physical characteristics and the way that a user will interact
with it.

For information regarding the differences between a user interface and the user experience, see the Glossary.

Some devices are adaptable, e.g. a tablet with a keyboard plugged in, or a
convertible laptop with only the touchscreen in use. These types of devices
will require the user interface to adapt as necessary for each usage mode.
If minimal changes are needed (for example, a laptop plugged into a large
external screen) this can be achieved with a “responsive” design, as described
in Responsiveness. For more extensive changes (for example, a tablet
plugged into a docking station with a mouse and keyboard attached), an entirely
different user interface paradigm may need to be presented.

Since there is sufficient space, all components are directly accessible and
multiple applications can be shown at once. The use of a keyboard allows quick
and efficient text input without any on-screen elements. Pointing devices are
highly accurate and user interface elements may be compact.

Though mouse-over (or “hover”) effects are possible, using them to hide functionality is discouraged, as it impedes usability and makes convergence more
difficult. Hover effects should only be used for non-essential informational
purposes, such as displaying tooltips.

It is possible to extensively customize the user interface to match the user’s
workflow and aesthetic preferences.

Laptops should be properly supported, keeping in mind the following guidelines:

When using a touchpad’s two-finger scroll gesture, ensure that scrollviews do
pixel-by-pixel scrolling instead of “jumping” certain number of rows.

Minimize window chrome and make sure that there’s enough space for content;
avoid excessive toolbars and frames. Not everything needs to be visible all
at the same time!

Minimize the use of Function keys as shortcuts, as these can be difficult to
access with a laptop keyboard. Provide alternative accelerators wherever
possible.

Don’t require right-clicking or middle-clicking for core functionality, as
these can be difficult or impossible to simulate with a touchpad. In
particular, never require the use of a right-click-drag or middle-click-drag.

The characteristics of the touch input method dominate the design. User
interface elements must be large enough to be accurately tapped by even the
largest fingers. Sloppy input should be corrected by intelligent software,
especially for textual input.

The main focus is the Application Content. Because of limited screen space, the
workspace hides as much as possible. Applications should only show contextually
appropriate content and tools, making the greatest possible use of the small
screen space. Application windows should be opened maximized, with side-by-side
or quarter tiling possible for larger tablets.

Like with the tablet device type, user interface elements must be large enough
to accommodate a large low-precision fingertip. Because of the even more
constrained screen size, only a few interactive controls can be presented at
one time. Others must be hidden on other pages or behind drawers and pop-up
views.

Like the tablet mode, the workspace hides as much as possible and the main focus
is the Application Content–only even more so. Great care must be taken to
optimize the Application Content to the small screen size, omitting anything
not absolutely necessary

While this device type is optimized for one-handed use, it may sometimes be
useful to support two-handed use, especially when typing.

Application-Workspace Interaction: Available from the Active Application
Overview, and allows closing and re-arranging/re-ordering apps

Application: Always runs fullscreen

Application Tools: The absolute minimum possible assortment of tools
are available from a toolbar within the application window. No desktop-style
menubars are used. Commonly-used tools can be accessed through touch gesture
shortcuts

Application Content: Needs to conform to the KDE HIG in order to display
content in a way that’s suitable for this device type